Electrical multiconductor cable connecting assembly



March 12, 1968 R. M. JANOWIAK ETAL 3,373,243

ELECTRICAL MULTICONDUCTOR CABLE CONNECTING ASSEMBLY 2 Sheets-Sheet 1Original Filed March 15, 1965 INVENTORS w vgwwwvvvuwvvvvmw 722221 Ma1968 R. M. JANOWIAK ETAL 3,373,243

ELECTRICAL MULTICONDUCTOR CABLE CONNECTING ASSEMBLY 2 Sheets-Sheet 2Original Filed March 15, 1965 mm Q m% vm M Q mm \v m /////A wn S Q mm W\m m Q mm m \Q NQ 3 j Qm mm B il lm Hv I l 1 \m .1 VI] mm m om vw Q Q Qmm Q United States Patent Office 3,373,243 Patented Mar. 12, 19683,373,243 ELECTRICAL MULTICONDUCTOR CABLE CONNECTING ASSEMBLY Robert M.Janowiak, Chicago, Joseph S. Conway, Freeport, and Walter J. Swistek,Chicago, Ill., and Edwin S. Oxner, Menlo Park, Calif., assignors, bymesne assignments, to The Bendix Corporation, Detroit, Mich., acorporation of Delaware Continuation of application Ser. No. 451,675,Mar. 15, 1965, which is a division of application Ser. No. 48,534, Aug.9, 1960, now Patent No. 3,209,287, dated Sept. 28, 1965. Thisapplication June 6, 1966, Ser. No. 587,338

6 Claims. (Cl. 174-89) ABSTRACT OF THE DISCLOSURE An electricalmulti-conductor cable connecting assembly wherein a sleeve and collarcoact to compress the jacket and shield of the cable between the collarand a tapered inner ferrule, with the cable inner conductor anddi-electric passing centrally through the ferrule.

This application is a continuation of application Ser. No. 451,675 filedMar. 15, 1965, now abandoned, which was a division of the priorco-pending application, Ser. No. 48,534, filed Aug. 9, 1960, entitled,Electrical Coaxial Cable Connecting with Impedance Matching, whichissued on Sept. 28, 1965, as Patent No. 3,209,287.

The present invention deals with electrical connectors and moreparticularly, is directed to the multi-conductor or co-axial typeconnector assembly.

Up to the present time most coaxial connectors have required fanning ofthe cable braid in the normal assembly procedure. A technique to obviatethe fanning process is a special clamping device in the form of twosleeves which are passed under and over the cables outer conductor andthen stamped, under extreme pressure, by a stamping machine. In both ofthe types mentioned a gasket must be included at the rear of theconnector to effect a water seal. Furthermore, the second type ofconnector mentioned is not reusable. That is to say, the stamped sleevemust be replaced since it is permanently affixed to the coaxial cable.

In the case where braid fanning is required, a discontinuity may existat the interface of the cable braid and the connector body resulting inunwanted reflections of transmitted signal. Absent a discontinuity theradius of the outer conductor may change hence, the characteristicimpedance would change. The characteristic impedance of a coaxial lineis defined as:

wherein, Z is the characteristic impedance, b is the diameter of theouter conductor, a is the diameter of the inner conductor and E, is therelative dielectric constant of the medium therebetween. An abruptchange in Z like a discontinuity results in wave reflection along atransmission line.

In contradistinction to the teachings and practices of the prior art wehave designed a unique, reusable connector assembly having aself-sealing feature and one that is substantially reflection free.

It is accordingly, a general object of the instant invention to providean improved connector assembly of the type described.

Another object of the instant invention is to provide a coaxialconnector oflering good radio frequency performance coupled with ease ofassembly.

Another more specific object of the instant invention is to provide acoaxial radio frequency connector having excellent cable grippingproperties.

Yet another object of the instant invention is to provide a coaxialcable connector wherein fanning of the cable braid is not necessary.

Yet still another more specific object of the instant invention is toprovide a radio frequency coaxial cable connector which is reusable andwhich forms a natural water seal without a gasket.

The invention possesses other objects and features of advantage which,with the foregoing, will become apparent to the reader in the followingdetailed description of the preferred form of the invention which isillustrated in the accompanying drawings as forming a part of thespecification.

Referring to the drawings wherein like reference numerals denote likeparts:

FIGURE 1 is a view, in cross section, of the left end of a completelyassembled connector plug.

FIGURE 2 is a side view of a coaxial cable with some of the plugcomponents mounted thereon, illustrating the manner of assembly.

FIGURE 3 is a side view of a coaxial cable with a completely assembledconnector plug.

FIGURE 4 is an exploded view of the structure shown in FIGURE 1.

FIGURE 5 is a side view of a preferred form of connector assemblycomprising a plug and jack.

FIGURE 6 is a view in cross section of the plug illustrated in FIGURE 5.

FIGURE 7 is a view in cross section of the jack illustrated in FIGURE 5.

Briefly stated, the foregoing objects and others are accomplished by aunique design and cooperation of a hollow externally threaded collar, aferrule having a frusto-conical projection and a sleeve for engaging thecollar. The ferrule, in addition to providing excellent electricalcontact with the cable braid, provides clamping pressure to outerconductor and insulation of the cable between the ferrule and the innersurface of the threaded collar.

While the invention has been shown and will be described in some detailwith reference to a particular, exemplary embodiment thereof, there isno intention that it be limited to such detail. Quite to the contrary,it is intended here to embrace all modifications, alternatives andequivalents falling within the spirit and scope of the invention asdefined by the appended claims.

Referring to FIGURES 1 and 4, a coaxial cable 19 comprising centerconductor 23, dielectric 22, outer conductor (cable braid) 21 and rubberjacket is shown. A hollow externally threaded collar 11 having ahexagonal flange is provided and adapted to frictionally engage jacket20. Such engagement is effected by having the minimum diameter of collar11 nearly equal to the outer diameter of cable 19. In the exemplaryarrangement, collar 11 has successively increased internal diametersections 11a, 11b and lie along the body thereof which define shoulders.As may be seen, the shoulders are disposed along a tapered planerelative to one another and the collar 11, therefore, substantiallydefines a tapered, conical inner surface.

Ferrule 13, having an annular flange 14 and a wedgeshaped projection isadapted to be inserted between dielectric 22 and outer conductor 21. Theinner diameter of ferrule 13 is nearly equal to the external diameter ofdielectric 22. An internally threaded sleeve 15, is provided to receivecollar 11. The wedge-shaped portion of ferrule 13 cooperating withcollar 11 and sleeve 15 is forced into a position whereby it appliesradial pressure to braid 21 and rubber jacket 20. This pressure is ofsufiicient magnitude to insure excellent engagement of cable 19.Likewise, this pressure forces jacket 24 into a confined volume andthereby creates a waterproof seal in addition to providing excellentradio frequency contact between the outer conductor 21 and ferrule 13.Additionally, as may be seen, the ferrule 13 and the collar 11 define anannular chamber therebetween axially adjacent the ferrule into which thesection Zita of the jacket 2% is forced into sealing relationship withthe sleeve 15. In the exemplary arrangement, the section 20a of thejacket is forced into sealing relationship with the inner threads of thesleeve 15. However, it will be readily apparent to those skilled in theart that the sleeve 1.5 may be designed so that the jacket section 20ais forced into sealing relationship with a nonthreaded portion of thesleeve.

The fiat end of ferrule 13 abuts the shoulder 15b in sleeve 15 andinsures proper positioning of ferrule 13 when the plug is assembled.Sleeve 15 has an opening, large enough to pass dielectric 22 and centerconductor 23 into its tubular portion 150 enabling connection to contactpin 18.

After cable 19 is trimmed, collar 11 is slipped thereover. Next ferrule13 is inserted between conductor 21 and dielectric 22. Contact pin 18 ispassed over a bare projecting end of conductor 23 and soldered thereto.Following this, sleeve 15 is journaled onto the cable passing overferrule 13. Collar 11 is brought into engagement therewith and thethreaded portion 12 thereof is screwed into the body of sleeve 15. Ahexagonal head 150, on sleeve 15, provides a gripping surface fortightening the connection between collar 11 and sleeve 15. Seat 15burges ferrule 13 under braid 21, and into its proper position, as theconnection between collar ill and sleeve 15 is secured.

In securing collar I1 and sleeve 15, ferrule 13 is properly positioned.In this position the transmission line experiences no discontinuity orchange in radius because ferrule 13 is a conductor and its inner radiusis equal to that of outer conductor 21. The pressure on jacket Ztlprovides waterproofing. The internally stepped portions 11a, 11b and 110of ferrule 11 enhance this characteristic in addition to providingeminently good cable-gripping properties. Furthermore, the section 20aof jacket 2% is forced into sealing relationship with sleeve 15 toprevent water leakage between sleeve 15 and collar ii.

A member 16, concentric with sleeve 15 and passing .thereover, is shownin position in FIGURE 3. Member 16 is adapted for locking engagementwith a jack having a female contact pin 32 (see FIGURE 7) adapted tomate with contact pin 13.

Reference now to FIGURES and 6, the composite connector assemblyincluding the complementary or righthand end thereof is shown. Theright-hand end of the connector assembly will hereinafter be referred toas the jack. In this embodiment the connector clamp structure issomewhat modified as will be described hereinbelow. Collar 11 andferrule 13 are substantially identical to those previously illustratedand function in the same manner. On the other hand, sleeve 15 is made upof two separate parts 15d and 15a. This change in design was primarilyfor ease of manufacturing. In assembly, parts 15d and 15e are mated andstamped together. It is noted that member 15d has a circumferential seattherein adapted to accommodate an annular ridge on ferrule 13 ofdiameter nearly equal to the seal on member 15d. This arrangementinsures proper alignment of ferrule 13.

Member 16 encircles a portion of sleeve 15d and defines a cavitytherebetween. Positioned Within said cavity is spring 26 which isarranged to urge member 16 to the left as far as it will go, in thisparticular case, to the point where member 16 abuts a hexagonal flange15 Guideway 24 on member 16 is provided for locking engagement with thejack having bayonet type locking fingers 3-1 projecting radiallytherefrom. In this particud lar embodiment three locking fingers 31spaced apart were used satisfactorily.

A dielectric insert 27 is secured in position in the connector body bymeans of crimping at 41 in FIGURE 6. Contact fingers 29 are secured toand spaced around the outer surface of dielectric 2'7 and providefrictionalengagernent with the inner surface of sleeve 3% of the ackshown in FIGURE 7. Positioned within the cavity defined by member 15 isan elastomer ring 28 which becomes compressed when the connector plug isin locking engagement with jack and provides a Watertight sealtherebetween.

Referring next to FIGURE 7, the jack assembly 1s shown. Female contactpin 32 is soldered to the center conductor 23 of another coaxial Cable.Contact pin 32 is adapted to mate with contact pin 18. Dielectric 33 isjournaled into the cavity defined by sleeve 36 and is fixed therein bycrimping at points 34. When the plug and ack are mated, dielectricinserts 27 and 33 take the form of one continuous dielectric section.

Frojecting from sleeve 3d are bayonet prongs 31 for locking engagementin guideways 24 of member 16. Sleeve fail is both internally andexternally threaded. The sleeves internal threads cooperate with collar39 exactly as was done in the connector plug body with collar 11 andsleeve 15.

The jack body may be adapted for panel mounting and in that case sleeve3d is provided with an outward radial flange 38. A rubber washer 37seated in hexagonal flange 38 abuts the inner wall of said panel. Washer36 and nut 35 are passed over the left end of the jack and engaged tothe outer threads of sleeve 30 to secure the jack, which has been passedthrough an opening in the panel, to the equipment. By tightening nut 35,a watertight seal is created between the jack and the panel.

Because of the special cable clamping technique in the design of theinstant invention, a discontinuity free path from the cable to the plugbody is achieved. In addition to a naturally formed water seal, theconnector assembly has good gripping action and is reusable.

In one embodiment, the clamp withstood a static load of seventy poundsfor over fifteen minutes and failed after more than one thousand, ninetydegree fiexures with a five pound load. The failure noted in the flexuretest was not in the connector gripping area, but due to a severance ofthe outer braid at the rear of collar 11.

From the foregoing, it is noted that We have provided a connector havinggood radio frequency performance, ease of assembly and with excellentcable gripping properties which represents a considerable advance overthe prior art.

It will be understood that the invention can be practiced otherwise thanhas been specifically described and is limited only by the scope of theappended claims. For example, the connector may be utilized to secureother forms of current carrying elements. Also, the connector may beused for splicing cables together as well as connection to panelmountings.

We claim:

1. An electrical cable connecting assembly comprising: a free end of amulticonductor cable which includes a central conductor, an outerconductive shield, a dielectric interposed between said conductor andsaid shield, and a connector comprising a collar the inside surface ofwhich is made up of a plurality of successfully increasing internaldiameter sections which define shoulders the edges of which are disposedalong a tapered plane relative to one another, said collar beingdisposed around said jacket with the enlarged portion of said taperedinner surface being adjacent said free end, an electrically conductivetubular Wedge-shaped member having an inner diameter corresponding tothe inner diameter of said shield and an outer wedge-shaped surfacecorresponding to the tapered plane defined by the shoulders of saidinner surface of the collar, said wedge-shaped member being disposed onsaid dielectric with said outer wedge-shaped surface engaging saidshield whereby said shield and said jacket are clamped between saidcollar and said wedgeshaped member and whereby said wedge-shaped memberis in electrically conductive relationship with said shield, and hollowsleeve means engaging said wedge-shaped member in abutting relationshipand cooperatively engaging said collar to urge said wedge-shaped memberinto compressive engagement with said collar, said jacket coacting withsaid collar, said seeve means, and said wedgeshaped member whereby saidjacket seals said assembly against the ingress of moisture.

2. The electrical cable connecting assembly of claim 1 wherein saidinner surface of said collar comprises a series of concentric wallportions of increasing stepped internal diameters providing saidshoulders which engage said jacket in a clamping relationship.

3. The electrical cable connecting assembly of claim 1 wherein the outersurface of said wedge-shaped member has a gradual taper engaging theinner surface of said shield in opposition to engagement of the outersurface of said jacket by said collar.

4. The electrical cable connecting assembly of claim 2 wherein saidcollar and said sleeve means are in threaded engagement whereby thecompressive force is exerted on said jacket to form a seal With saidinner surface of said collar and with an inner surface of said sleevemeans.

5. The electrical cable connecting assembly of claim 4 wherein anannular Wall extends outwardly from the larger end of said wedge-shapedmember, said annular wall compressing said jacket and urging said jacketoutwardly into sealing engagement with the inner surface of said sleevemeans.

6. The electrical cable connecting assembly of claim 4 including a rigidcentral conductive connector member secured to said cable conductor anda connector dielectric disposed between said central connector memberand said sleeve, said connector dielectric abutting the dielectrio ofsaid cable.

References Cited UNITED STATES PATENTS 1,326,250 12/1919 Brown et al.285-246 2,901,085 8/1937 Scholtes 285-250 2,441,718 5/1948 Parker et al.285-149 2,805,399 9/1957 Leeper 174-7 X 2,809,056 10/1957 Kaiser285--149 2,906,809 9/1959 Drenning 17488 X 3,209,287 9/ 1965 Oxner 17489X DARRELL L. CLAY, Primary Examiner.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTIONPATENT NO. 3,373,243

DATED March 12, 1968 |NVENTOR(S) I R. M. JANOWIAK ET AL It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 4, line 63, after the word and punctuation "shield,"

insert the words -and a resilient insulating jacket surrounding saidshield Bigncd and Scaled this A nest:

LUTRELLE F. PARKER RUTH MASON Arresting Oflicer Acting Commissioner ofPatents and Trademarks

